>
> Date: Tue, 23 Mar 2010 08:31:13 -0700
> From: Al Kossow <aek at bitsavers.org>
> On 3/23/10 4:09 AM, Julian Skidmore wrote:
>>
>> Alexey Toptygin wrote:
>>
>>> What's wrong with pulse or async logic designs? I personally find them
>>> fascinating, but I've never gotten to play with an implementation of
>>> one... Are there problems with designing like this that made people
>>> switch
>>> to sync designs? Anyone know of any good books on non-synchronous logic
>>> design?
>>
>> Probably the best resources are the Amulet resources from Manchester
>> University.
>>
>
> Or the work on logical effort by Ivan Sutherland.
I did some contract design work for a company called Theseus (Mumble) back
around 2000. Their stuff was all non-clocked logic. They used two rails
per bit and depending on how the two rails were coded it represented
either 0, 1 or ready (or finished?), if I remember correctly.
The logic to signal back the completion and readys about doubled the
amount of real estate the logic used, but it could run as fast as the
gates allowed, did not have a synchronizing pulse, making remote
monitoring attacks difficult to impossible and only used as much power as
it needed to process the actual data available.
The amount of design discipline needed was substantial, making me wonder
if just going to the trouble of implementing more traditional power saving
techniques wasn't a better option.
Jeff Walther
There's a contest with a prize of a new Toshiba laptop that goes to the
person with the oldest working Toshiba laptop:
http://www.facebook.com/toshibaportugal?v=app_7146470109
(it's in Portuguese).
You must be a Portuguese citizen.
Bill
"Jeremy S. Sharp" <theodric at gmail.com> wrote:
> Is there anybody here who keeps classic big(-ish) iron running 24x7?
> I've been told a story of a burning PDP-11/34 which has somewhat put
> me off any notion of leaving my -8s turned on when I'm not within
> reach of a killswitch & fire extinguisher. :)
At the moment, nothing more than my 11/93. Current uptime about a month.
I used to manage an 11/70 as well. It's still on standby, but powered
down most of the time right now because of cooling problems, and
electricity bill. (Same with a VAX-8650.)
Johnny
Date: Mon, 22 Mar 2010 18:04:26 -0600
From: Andrew Warkentin <andreww591 at gmail.com>
Subject: Wanted: Graphics card and drive sled for RS/6000 7046-B50
>I recently bought an RS/6000 7046-B50. It didn't have a graphics card
>installed (I can use it over a serial console, but I would prefer to be
>able to use a graphical console). It is also missing the drive sleds.
>Does anybody have a graphics card or drive sled that would work with it?
----------
A few days ago I posted here about an RS/6000 available in the Toronto
area but there was no interest either here or elsewhere, so it's being
scrapped on Thursday.
This is an RS/6000 Power Server 520, Type 7013, Model# 26-10855;
If it has a graphics card would it fit in yours and what would the number be?
And are the sleds compatible?
mike
On 22/03/2010 19:18, Alex Taylor wrote:
> The idea was that reformatting a 1.44MB HD disk in a DD drive will
> leave traces of the original formatting behind (as they're always
> preformatted for DOS/Windows), causing the unreliability. Using a bulk
> eraser is meant to eliminate this problem, as it will turn them into
> completely blank disks that can be formatted in a DD drive more
> reliably.
That won't really matter. When you format a disk you write bit patterns
all over it: in the headers, in the data sectors, and even in much of
the gaps between them (sync bytes and clock patterns used as markers).
Thus there's something there even when you write the first real data,
and of course it never lines up exactly, bit for bit. Therefore you
still have the problem of interference from the previous "data" even if
it's just the dummy data used to fill a "blank" sector, and the sync
bytes and markers in the preamble to it.
--
Pete Peter Turnbull
Network Manager
University of York
I don't know what the market is like in Europe, but I can still buy new media in 5.25" and 3.5" format easily here in the U.S.
Google brings up many places here.
If there are no such outlets in the UK, maybe you can get a bulk order together with some local folks to save on the shipping costs?
Al
From: Liam Proven <lproven at gmail.com>
Subject: Reusing old floppy *drives*
Noting the discussion on old media, a slightly different question.
Please excuse my profound ignorance on matters electronic!
I have read, somewhere, that it is possible to connect HD floppy
drives to elderly kit that is only expecting DD drives, and use them
for just DD operation.
More specifically, I'd like to resurrect my ancient Sinclair Spectrum
with its MGT DISCiPLE disk interface. Way back in the 1980s, I used
5?" media, as they were still cheaper. However, now, I daresay I won't
find any new 5?" media and even 3?" DD media are getting tricky.
So what I was considering doing was connecting a pair of old PC floppy
drives - 3?" HD (1.4MB) floppies - and quite possibly using 1.4MB
media, but only formatting them to 720K and using them as 720K. IIRC,
the drives permit this.
The track widths are the same - both are 80t drives - it's just that
DD used 9 sectors per track and HD 18.
Is this likely to work? I realise I'll need to find drives with a unit
selection jumper on them, so I can set one as 0 and the other as 1; no
twists in the cables this far back, & I'm guessing that a twisted
cable wouldn't work with a controller that wasn't expecting it...?
--
Liam Proven ? Profile: http://www.linkedin.com/in/liamproven
Email: lproven at cix.co.uk ? GMail/GoogleTalk/Orkut: lproven at gmail.com
Tel: +44 20-8685-0498 ? Cell: +44 7939-087884 ? Fax: + 44 870-9151419
AOL/AIM/iChat/Yahoo/Skype: liamproven ? LiveJournal/Twitter: lproven
MSN: lproven at hotmail.com ? ICQ: 73187508
Hello,
I have the following Tek Instruction Manuals sitting here. I would
like to free up the space they are consuming. If someone wants to make
it worth my while to spend the time shipping them out, I will
entertain offers. Otherwise, I will dump them in the recycling.
Preference will go to the fewest number of boxes I have to deal with
and, of course, compensation offered. I will accept offers until
Sunday (28th) evening. I will ship or recycle Monday.
Shipping from 53714.
Jon
--
7904 Oscilloscope operators
7904 Oscilloscope Service
7A13 Differential Comparator
7A19 Amplifier
7A26 Dual Trace Amplifier
7B92A Dual Time Base
7B80 Time Base
7B85 Delaying Time Base
7M11 50-Ohm Delay Line
S-6 Sampling Head
S-52 Pulse Generator Head
S-53 Trigger Recognizer Head
C-5C Camera
2215 Oscilloscope Service
P6056/P6057 Probe
P6131 Passive Probe
P6460 Data Acquisition Probe
K212 Portable Instrument Cart
1240 Workbook
I also have "data sheets" for the following items:
P6063B Passive Probe
200C Scope-Mobile Cart
Hello,
Does anybody have the source code and libarays for the old MEWEL windows interface?
I have been looking for this so the source code for a Juki Pick and Place machine can be updated.
If there is a fee for this, just let me know.
Thanks,
Patrick McLeod
McLeod Instruments, Ltd.
928-535-6369
Alexey Toptygin wrote:
> What's wrong with pulse or async logic designs? I personally find them
> fascinating, but I've never gotten to play with an implementation of
> one... Are there problems with designing like this that made people switch
> to sync designs? Anyone know of any good books on non-synchronous logic
> design?
Probably the best resources are the Amulet resources from Manchester
University.
http://intranet.cs.man.ac.uk/apt/async/
In the late 90s they experimented with Asynchronous ARM processors.
The difficulty with asynchronous design is that it's far more prone to
race hazards than synchronous design. Also, they found that even the
simple handshaking protocol they used limits performance. Nevertheless,
they do have some advantages, for example their EMF emmissions tend to be
evenly spread across a broad spectrum.
Incidently, modern synchronous design is far less synchronous than it
used to be; high clock rates mean that CPUs are subdivided into
differently clocked domains to avoid clock skew.
-cheers from julz @p
>
> Message: 6
> Date: Tue, 16 Mar 2010 20:12:10 +1100
> From: Nigel Williams <nigel.d.williams at gmail.com>
> Subject: eBay Oz : Collection of DEC Unibus modules including custom
> To: "General Discussion: On-Topic and Off-Topic Posts"
> <cctalk at classiccmp.org>
>
All sorts of interesting items: TU-60, CM-11, M792 etc
>
> http://shop.ebay.com.au/pdp11.caps11/m.html?_nkw=&_armrs=1
>
> not connected with seller, however I did purchase fanfold paper-tape from
> this eBayer.
>
I'm the seller so blame me.... blatant plug follows :-)
I have to clear out my shed so I'll be dumping on eBay.com.au various bits
and pieces. Predominantly it will be DEC UNIBUS modules, papertape, CAPS-11
operating system, plus technical documentation. Stuff is coming out in
random order. E.g. some of the -K series laboratory modules have been listed
but I've only just found the panels and some of the cables.
Really only of interest to Australians are the heavy/bulky/delicate items
like the PDP-11 system with the LPS-11 / TU60, or FABRI-TEK Model 11 Add-On
Memory System, etc., that are being listed as local pickup. There will some
Heathkit (H10 papertape readers/punches and a 3400A microcomputer trainer)
plus should be some HP GPIB gear. The Tektronix gear has already gone. I do
not have any CM-11 card readers, just some of the UNIBUS interface modules.
Regards,
Garry